First of all I must confess that the Fomori have always been one of my favourite things in Werewolf. I quite liked Freak Legion and while Possessed brought the Fomori to the revised rules it's Autonomy trait was, in my opinion, poorly conceived and executed.
Now W20 had quick and simple system for creating Fomori but for me it relied too much on ST's whims as it left the Fomori powers entirely dependant on how well a Player succeeded in pleeding his/her case and convincing the ST to give out powers. Now Holden keeps things simple for Fomori character generation but adds a simple yet important mechanic to how powers are gained at character generation. He also brings back, as Flaws, many of the signature weaknessess of the Fomori introduced back in the Freak Legion. Personally I wouldn't have limited the Fomori to just 7 merit points total, though the rule does force more rounded and cabable, ability, background and attribute wise, characters as people must use a minimum of 14 freebies to buy traits.
I rather like the Fomori species templates provided with costs already calculated as it speed up the chargen process.
The new families provided are quite interesting and fun reads as well as shoving us certain evolution within a Fomori species.
The only downside really is that there is no character development advice or mechanic conserning the Fomori powers and how to develop new ones or evolve the ones already possessed. This is particularly sad since the Species covered in the first half of the book include some whom have evolved from a base Fomori type and gained both new powers and stronger versions of base powers. Still it is a truly minor issue in an otherwise excellent book well worth the it's cost.
Excellent resource for any ST wishing to include Fomori in their W20 games as antagonist and an essential resource for those wishing to have Fomori protagonists.